The government today said it is looking into problems faced by mobile phone users in changing service provider under the Mobile Number Portability service.

"Term cells have been asked to look into all the complaints and ensure that all the companies comply with the MNP. They will look into it and take the necessary actions," DoT secretary R Chandrasekhar told reporters here.

MNP that was launched across India on January 20 allows subscribers to change their service provider while retaining their phone numbers.

Customers wanting to use MNP service have complained of being told by telcos that their request can not be completed due to technical glitches.

To avail the MNP service, customers have to pay a maximum charge of Rs 19 to an operator to switch to another operator who has the option to either waive the fee or reduce it.

However, a consumer has to remain with one operator for a minimum period of three months in order to avail the MNP service.

According to GSM lobby COAI Director-General Rajan Mathews, technical glitches were bound to crop up in the first few weeks, especially considering the scale of the project.

The DoT has claimed that the entire process of switching operators will take a maximum of seven days and subscribers may face disruption of services for about two hours during that period.